The Persistence of Force. 87 



SECTION II. 



WHAT is INCLUDED IN THE TERM FORCE ? 



That there is no warrant for the acceptance of the 

 persistence of force as a regulative principle authori- 

 tative over the whole range traversed by human 

 intelligence will the more evidently appear from an 

 examination of its terms. 



First, let us inquire, What is included in the term 

 force ? We are familiar with force in its material 

 modes. We cognize it under the form of matter ; we 

 see it manifested in the movement of bodies ; we have 

 experience of it in affections of the organism ; we know 

 it in the effect produced in obedience to the will. 

 These experiences furnish us with the concept of 

 force. To these and the like instances the word is in 

 its original and proper signification limited. * In a 

 secondary or metaphorical sense, we apply the term to 

 express experiences of a wholly different nature. We 

 speak of intellectual force, of force of character, of 

 moral force, of the force of public opinion, including 

 in such usage a meaning altogether different from 

 that conveyed when we speak of the force of a blow. 



* Force is defined by Thomson and Tait as being "any cause 

 which tends to alter a body's natural state of rest or of uniform 

 motion in a straight line." Elements of Natural Philosophy, 

 Parti., 183. 



"Force in point of fact is a direct object of sense ; probably 

 of all our senses, and certainly of the muscular sense." Ibid. 

 173. 



